Post on 29-Apr-2023
Morphology tanah menunjukkan bentuk dan susunan penampakan tanah
Di lapangan, pengenalan bentuk morphology dilakukan melalui pengamatan, pendeskripsian dan analisa.
Observasi kadang dilakukan dengan bantuan lensa dan uji kimia sederhana (ph, keberadaan karbonat dll).
Pengamatan dan pengukuran kadang perlu dilakukan di laboratorium (kimia, biologi dan fisik)
Penyipfatan morphology diawali di profil tanah.
Deskripsi dilakukan dengan membatasi profil tanah berdasarkan horizon atau lapisan yang terlihat jelas.
Pembatasan horizon kadang bersifat subjectif karena batas antar horizon yang tidak jelas.
Interval kedalaman horizon atau lapisan (diukur dari bagian atas horizon)
Karakteristik batas horizon Warna Tekstur Struktur Porositas Konsistensi Perakaran pH Penampakan khusus; seperti selaput, nodul dan konkresi
Master HorizonsMaster HorizonsO organic A topsoil, O.M., cyclingE elluvialB developed/accumulationC parent materialR bedrock
A horizon
B horizon
C horizon
O horizon
E horizon
Organic matter
Sandy
Clays/iron
Parent
Didominasi oleh bahan organic Terdiri atas sebahagian litter yang sudah terdekomposisi pada bagian permukaannya
Merupakan bahan organic yang terkumpul pada lingkungan yang lembab dan sudah terdekomposisi.
Lapisan kaya bahan organic yang terbentuk dari translokasi bahan organic di dalam bahan mineral tidak disebut sebagai horizon O
Horizon mineral yang terbentuk di permukaan atau dibawah horizon O.Horizon A menunjukkan :•Akumulasi humus b.o yang bercampur dan fraksi mineral
•tidak menunjukkan dominasi horizon E atau B,
•akibat pengolahan tanah, penggembalaan atau berbagai hal yang mengubah tanah.
Horizon mineral yang kehilangan silikat liat, besi, alumunium atau kombinasinya
Mengandung partikel pasir dan debu serta berwarna cerah.
konsentrasi illuvial dari liat silikat, besi/ setrika, aluminium, karbonat, gypsum, atau humus
hilangnya karbonat silikat liat atau sesquioksida Warna lebih gelap atau merah dibanding bagian atas dan bawah tanpa adanya illuviasi besi
Horizon mineral yang masih sedikit mengalami proses pembentukan tanah
Horizon ini bisa mirip atau bahkan tidak menyerupai horizon A, E dan B
Distinctness
Abbreviation [cm]
Abrupt a < 2 Clear c 2 - 5
Gradual g 5 - 15
Diffuse d > 15
Topography Abbreviation Description
Smooth s Nearly a plane
Wavy w Waves wider than deep
Irregular i Depth greater than width
Broken b Discontinuous
Soil color Soil attributes Environmental conditions Brown to black (surface horizon)
accumulation of organic matter (OM), humus
low temperature, high annual precipitation amounts, soils high in soil moisture, and/or litter from coniferous trees favor an accumulation of OM
Black (subsurface horizon)
Accumulation of manganese or Parent material (e.g. basalt)
-
Bright-light Eluvial horizon (E horizon)
In environments where precipitation > evapotranspiration there is leaching of sequioxides, carbonates, and silicate clays. The eluviated horizon consists mainly of silica
Yellow to reddish Fe3+ (oxidized iron) Well-aerated soils
Gray, bluish-green Fe2+ (reduced iron)
Poorly drained soils (e.g. subsurface layer with a high bulk density causes waterlogging, or a very fine textured soil where permeability is very low), anaerobic environmental conditions
White to gray Accumulation of salts
In arid or subhumid environments where the evapotranspiration > precipitation there is an upward movement of water and soluble salts in the soil
White to gray Parent material: marl, quartz -
Soil texture Abbreviation
Gravel g Very coarse sand vcos Coarse sand cos Sand s Fine sand fs Very fine sand vfs Loamy coarse sand lcos Loamy sand ls Loamy fine sand lfs Sandy loam sl Fine sandy loam fsl Very fine sandy loam vfsl Gravelly sandy loam gsl Loam l Gravelly loam gl Stony loam stl Silt si Silt loam sil Clay loam cl Silty clay loam sicl Sandy clay loam scl Stony clay loam stcl Silty clay sic Clay c
Soils different in texture
Pore volume [%]
Macropores [%]
Medium-sized pores [%]
Micropores [%]
Sandy soils
46 (+/- 10)
30 (+/- 10)
7 (+/- 5)
5 (+/- 3)
Silty soils
47 (+/- 9)
15 (+/- 10)
15 (+/- 7)
15 (+/- 5)
Clayey soils
50 (+/- 15)
8 (+/- 5)
10 (+/- 5)
35 (+/- 10)
Organic soils
85 (+/- 10)
25 (+/- 10)
40 (+/- 10)
25 (+/- 10)
Grade Abbreviation Description
Structureless 0
No observable aggregation or no orderly arrangement of natural lines of weakness
Weak 1 Poorly formed indistinct peds
Moderate 2
Well-formed distinct peds, moderately durable and evident, but not distinct in undisturbed soil
Strong 3
Durable peds that are quite evident in undisplaced soil, adhere weakly to one another, withstand displacement, and become separated when soil is disturbed
Form Abbreviation Description
Granular gr Relatively nonporous, spheroidal peds, not fitted to adjoining peds
Crumb cr Relatively porous, spheroidal peds, not fitted to adjoining peds
Platy pl Peds are plate-like. The particles are arranged about a horizontal plane with limited vertical development. Plates often overlap and impair permeability
Blocky bk Block-like peds bounded by other peds whose sharp angular faces form the cast for the ped. The peds often break into smaller blocky peds
Angular blocky abk Block-like peds bounded by other peds whose sharp angular faces form the cast for the ped
Subangular blocky sbk Block-like peds bounded by other peds whose rounded subangular faces form the cast for the ped
Prismatic pr
Column-like peds without rounded caps. Other prismatic caps form the cast for the ped. Some prismatic peds break into smaller blocky peds. In these peds the horizontal development is limited when compared with the vertical
Columnar cpr
Column-like peds with rounded caps bounded laterally by other peds that form the cast for the peds. In these peds the horizontal development is limited when compared with the vertical
Single grain sg Particles show little or no tendency to adhere to other particles. Often associated with very coarse particles
Massive m A massive structure show little or no tendency to break apart under light pressure into smaller units. Often associated with very fine-textured soils.
Size
Angular and subangular blocky
structure[mm]
diameter
Granular and crumb structure
[mm] diameter
Platy structure[mm] width
Prismatic and
columnar structure
[mm] diameter
Very fine < 5 < 1 < 1 (very thin) < 10
Fine 5 - 10 1 - 2 1 - 2 (thin) 10 - 20
Medium 10 - 20 2 - 5 2 - 5 20 - 50
Coarse 20 - 50 5 - 10 5 - 10 (thick) 50 - 100
Very coarse > 50 > 10 > 10 (very thick) > 100
Moisture status Consistence Abbrev
iation Description
wet Nonsticky wso Almost no natural adhesion of soil material to fingers
Slightly sticky wss Soil material adheres to only one
finger
Sticky ws Soil material adheres to both fingers
Very sticky wvs Soil material strongly adheres to both fingers
Nonplastic wpo No wire is formable by rolling material between the hands
Slightly plastic wps
Only short (< 1cm) wires are formed by rolling material between the hands
Plastic wp
Long wires (>1cm) can be formed and moderate pressure is needed to deform a block of the molded material
Very plastic wvp Much pressure is needed to deform a block of the molded material
Moisture status Consistence Abbreviation Description
Moist Loose ml Soil material is noncoherent
Very friable mvfr Aggregates crush easily between thumb and finger
Friable mfr Gentle pressure is required to crush aggregates
Firm mfi Moderate pressure is required to crush aggregates
Very firm mvfi Strong pressure is required to crush aggregates
Extremely firm mefi Aggregates cannot be broken by
pressure
Moisture status Consistence Abbreviat
ion Dry Loose dl
Soft ds Slightly hard dsh Hard dh Very hard dvh Extremely hard deh
Moisture status Consistence Abbreviat
ion Cementation Weakly cemented cw
Strongly cemented cs Indurated ci
Root quantity classes Per unit area Very few < 0.2 Moderately few 0.2 to 1 Few < 1 Common 1 to < 5 Many >= 5
Size classes of roots Diameter in mm
Very fine < 1 Fine 1 - 2 Medium 2 - 5 Coarse 5 - 10 Very coarse > 10
Concentrations : Wajah tanah yang terbentuk oleh akumulasi bahan selama proses pedogenesis,; pelarutan, oksidasi, reduksi, fisik dan kimia, perpindahan dan penimbunan• Types:
Halus Massa Nodule Konkresi Kristal Biologis
Ped & Void Surface Features : merupakan selaput yang terbentuk oleh translokasi dan deposisi, atau proses mengembang mengerut, dijabarkan menurut jenis, banyaknya, tempat dan warna
b – buried horizon c – concretions d – root restrictive g – gleying h – illuvial organic matter k – carbonates m – cementation o - oxic p – plowing/disturbance q – secondary silica r – soft bedrock (saprolite) s – illuvial sesquioxides and O.M. t – clay accumulation v – plinthite w – development of color/structure x - fragipan
Subordinate Distinctions
g – gleying h – illuvial organic matter p – plowing/disturbance t – clay accumulation w – development of color/structure o – oxic
• Keadaan reduksi, jenuh air.• Reduksi Besi (Fe III to Fe II)• Chroma rendah• Ditemui pada horizon master B (Bg horizon), E dan C.
gleyedmaterial
oxidizedmaterial
oxidizedFe3+
Fe2+
Subordinate Distinction
• Akumulasi illuvial organic matter-metal complexes•h = “humic”• value dan chroma < 3• Digunakan pada master horizon B (Bh)
Bh horizon“spodic horizon”
*
Subordinate Distinction
Horizon permukaan yang terganggu (pengolahan, peternakan, kehutanan)Digunakan pada master horizon A (Ap)
Ap horizon
Subordinate Distinction
• Translokasi liat• Fgunakan pada master horizon B (Bt)• dapat digunakan pada sub horizon g (Btg)
Subordinate Distinction
o = oxic horizon
Akticitas liat rendahMaterial terlapukkan sedikitStruktur batuan sedikitOksida Fe dan Al
Subordinate Distinction
Menunjukkan tingkat pelapukan bahan organik pada horizon O.
Oa – highly decomposed (sapric)Oe – moderately decomposed (hemic)Oi – slightly decomposed (fibric)
Sapric –most decomposed, low plant fiber, low water contentHemic – intermediate decompostionFibric – least decomposed, recognizable fibers
Subordinate Distinction
Characterized by similar master and/or subordinateproperties separated by “degree”.
Bt1
Bt2
Bt3
Bt horizons